On conduction in a bacterial sodium channel.
Voltage-gated Na⁺-channels are transmembrane proteins that are responsible for the fast depolarizing phase of the action potential in nerve and muscular cells. Selective permeability of Na⁺ over Ca²⁺ or K⁺ ions is essential for the biological function of Na⁺-channels. After the emergence of the firs...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS Computational Biology |
| Online Access: | http://europepmc.org/articles/PMC3320569?pdf=render |
| _version_ | 1818180298215522304 |
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| author | Simone Furini Carmen Domene |
| author_facet | Simone Furini Carmen Domene |
| author_sort | Simone Furini |
| collection | DOAJ |
| description | Voltage-gated Na⁺-channels are transmembrane proteins that are responsible for the fast depolarizing phase of the action potential in nerve and muscular cells. Selective permeability of Na⁺ over Ca²⁺ or K⁺ ions is essential for the biological function of Na⁺-channels. After the emergence of the first high-resolution structure of a Na⁺-channel, an anionic coordination site was proposed to confer Na⁺ selectivity through partial dehydration of Na⁺ via its direct interaction with conserved glutamate side chains. By combining molecular dynamics simulations and free-energy calculations, a low-energy permeation pathway for Na⁺ ion translocation through the selectivity filter of the recently determined crystal structure of a prokaryotic sodium channel from Arcobacter butzleri is characterised. The picture that emerges is that of a pore preferentially occupied by two ions, which can switch between different configurations by crossing low free-energy barriers. In contrast to K⁺-channels, the movements of the ions appear to be weakly coupled in Na⁺-channels. When the free-energy maps for Na⁺ and K⁺ ions are compared, a selective site is characterised in the narrowest region of the filter, where a hydrated Na⁺ ion, and not a hydrated K⁺ ion, is energetically stable. |
| first_indexed | 2024-12-11T21:17:32Z |
| format | Article |
| id | doaj.art-0e28717795504cc6a7ea0942fb074c2d |
| institution | Directory Open Access Journal |
| issn | 1553-734X 1553-7358 |
| language | English |
| last_indexed | 2024-12-11T21:17:32Z |
| publishDate | 2012-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Computational Biology |
| spelling | doaj.art-0e28717795504cc6a7ea0942fb074c2d2022-12-22T00:50:32ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582012-01-0184e100247610.1371/journal.pcbi.1002476On conduction in a bacterial sodium channel.Simone FuriniCarmen DomeneVoltage-gated Na⁺-channels are transmembrane proteins that are responsible for the fast depolarizing phase of the action potential in nerve and muscular cells. Selective permeability of Na⁺ over Ca²⁺ or K⁺ ions is essential for the biological function of Na⁺-channels. After the emergence of the first high-resolution structure of a Na⁺-channel, an anionic coordination site was proposed to confer Na⁺ selectivity through partial dehydration of Na⁺ via its direct interaction with conserved glutamate side chains. By combining molecular dynamics simulations and free-energy calculations, a low-energy permeation pathway for Na⁺ ion translocation through the selectivity filter of the recently determined crystal structure of a prokaryotic sodium channel from Arcobacter butzleri is characterised. The picture that emerges is that of a pore preferentially occupied by two ions, which can switch between different configurations by crossing low free-energy barriers. In contrast to K⁺-channels, the movements of the ions appear to be weakly coupled in Na⁺-channels. When the free-energy maps for Na⁺ and K⁺ ions are compared, a selective site is characterised in the narrowest region of the filter, where a hydrated Na⁺ ion, and not a hydrated K⁺ ion, is energetically stable.http://europepmc.org/articles/PMC3320569?pdf=render |
| spellingShingle | Simone Furini Carmen Domene On conduction in a bacterial sodium channel. PLoS Computational Biology |
| title | On conduction in a bacterial sodium channel. |
| title_full | On conduction in a bacterial sodium channel. |
| title_fullStr | On conduction in a bacterial sodium channel. |
| title_full_unstemmed | On conduction in a bacterial sodium channel. |
| title_short | On conduction in a bacterial sodium channel. |
| title_sort | on conduction in a bacterial sodium channel |
| url | http://europepmc.org/articles/PMC3320569?pdf=render |
| work_keys_str_mv | AT simonefurini onconductioninabacterialsodiumchannel AT carmendomene onconductioninabacterialsodiumchannel |